/Engine/Source/Runtime/Navmesh/Public/Recast/Recast.h
rcHeightfield
struct rcSpanData
unsigned int:  ...
area
The area id assigned to the span.
rcSpanUInt:  RC...
smax
The upper limit of the span. [Limit: <= #RC_SPAN_MAX_HEIGHT].
rcSpanUInt:  RC...
smin
The lower limit of the span. [Limit: <smax].